Combining crop diversification practices can benefit cereal production in temperate climates

Abstract

Diversifying cropping systems by increasing the number of cash and cover crops in crop rotation plays an important role in improving resource use efficiency and in promoting synergy between ecosystem processes. The objective of this study was to understand how the combination of crop diversification practices influences the performance of arable crop sequences in terms of crop grain yield, crop and weed biomass, and nitrogen acquisition in a temperate climate. Two field experiments were carried out. The first was a 3-year crop sequence with cereal or grain legume as the first crops, with and without undersown forage legumes and forage legume-grass crops, followed by a cereal crop. The second experiment was a 2-year crop sequence with cereal or legume as the first crops, a legume cover crop, and a subsequent cereal crop. For the first time, crop diversification practices were combined to identify plant-plant interactions in spatial and temporal scales. The results partly confirm the positive effect of diversifying cereal-based cropping systems by including grain legumes and cover crops in the crop sequence. Legume cover crops had a positive effect on subsequent cereal grain yield in one of the experiments. Using faba beans as the first crop in the crop sequence had both a positive and no effect on crop biomass and N acquisition of the subsequent cereal. In cover crops composed of a forage legume-grass mixture, the grass biomass and N acquisition were consistently increased after the grain legume, compared to the cereal-preceding crop. However, differences in the proportion of legume to grass in mixture did not influence crop yield or N acquisition in the subsequent cereal. In conclusion, these results support that increased crop diversity across spatial and temporal scales can contribute to resource-efficient production and enhance the delivery of services, contributing to more sustainable cropping systems.

Global systematic review with meta-analysis reveals yield advantage of legume-based rotations and its drivers

“…These services potentially reduce the dependence on external inputs while maintaining high crop yields and production stability 1 , 4 . Diversification through the inclusion of legumes in cereal-, root-, or tuber-based cropping systems represents a key strategy for sustainable agriculture 3 , 5 , 6 . However, legume cultivation has declined globally in recent decades due to their low and unstable yields, leading to reduced high-quality protein production and loss of ecosystem services 7 , 8 .…”

Agronomic performance, nitrogen acquisition and water-use efficiency of the perennial grain crop Thinopyrum intermedium in a monoculture and intercropped with alfalfa in Scandinavia

“…However, the legume companion is expected to supplement some of the nutrient requirements with time and the tendency of increased fixation of nitrogen from the atmosphere somewhat meets this expectation. This tendency reflects the interspecies interaction in intercrops of cereals and legumes, where the cereal most often acquires a larger proportion of the soil N in comparison to its proportional abundance, which leads to increased N 2 fixation in the grain legume crop (Rodriguez et al 2021). On the other hand, Li et al (2019) identified a need for fertilisation to support the development of IWG in the establishment phase when intercropped with alfalfa, possibly indicating that alfalfa is too aggressive for intercropping with IWG, at least when established at the same time point.…”

Using perennial plant varieties for use as living mulch for winter cereals. A review

“…Similarly, multi-species living mulch could offer advantages compared to a mono-specific living mulch. Especially in the period between two crops, when the living mulch acts like a cover crop, specific interactions could lead to greater biomass production or N fixation compared to a mono-specific cover like it is the case for annual cover crops (Wendling et al 2017;Rodriguez et al 2021) During the growing period of the cereal on the other hand, increasing inter-and intra-specific variation must not result in a living mulch with a greater ability to exploit the resources and in a stronger competition with the cereal crop. Indeed, the presence of various species and/or cultivar within the canopy might contribute to the required tradeoff between fast covering the ground for preventing weeds and limiting maximum production for reducing competition for light.…”